Butter tub cover



A. M. WALSTROM BUTTER TUB COVER May 24, 1932.

Filed NOV. 17, 1930 Patented May 24, 1932 AXEL M. WALSTROM, OF MINNEAPOLIS, MINNESOTA BUTTER TUB COVER Application filed November 17, 1930.

My invention relates to means for securing wooden covers in place on wooden pails and tubs, and which is especially designed to be i used with the coopered containers now gen- 6 erally used for shipping and storing butter.

An object of my invention is :a means for securing a cover to a tub in such manner that the cover will be firmly pressed into place 7 on the tub so that the contents of the tub will be more effectively sealed against the entrance of foreign matter and contaminating odors.

Another object of my invention is :a cover fastening rim provided with yielding edges which adapt themselves to uneven surfaces on both cover and tub so as to effect a sealed contact above and below the joint between said cover and tub, to further safeguard the contents of said tub. A further object of my invention is :a cover fastening means by which the use of nails or staples is eliminated, and which is readily detached to allow removal of the cover for inspection of the contents of the tub, and as readily replaced after such inspection.

My invention consists of the structural features described in the following specification, and as shown in the accompanying drawings,

in which Fig. 1 is a top view of a butter tub cover having my invention applied to the periphery thereof.

Fig. 2 is a side view of a butter tub having my improved cover fastening means.

Fig. 3 shows a portion of the cover securing rim and the manner of forming the telescoping slip-joint at the overlapping ends of said rim.

Fig. 4 is a top edge view of the rim portion shown in Fig. 3, and

Fig. 5 is an outside view of one end of said rim.

Fig. 6 is a cross-sectional view of the rim, taken on the line 6-6 of Fig. 3.

Fig. 7 is a cross-sectional view of a portion of the upper edge of a tub with my improved cover fastening means in normal position thereon, and

Fig. 8 is another cross-sectional view of Serial No. 496,174.

my improved rim, taken on the line 8-8 of Fig. 3. 1

1n the above described views, numeral 10 indicates a butter tub of the type now generally used, which is made up of a number of tapered wooden staves snugly drawn together by a series of metal hoops 11. A flat wooden cover 12 is'loosely placed on the top of the tub 10, and to adapt this cover for use with my invention I provide a downwardly inclined surface 18 at its upper edge, for the purpose hereinafter described.

As originally made, this cover is of substantially the same outside diameter as the upper end of the tub, but, it is a fact that such wooden covers shrink more or less across the grain thereof, even though they have been previously kiln dried, and frequent changes in atmospheric humidity also cause these covers to warp more or less before they are used. It is therefore evident that such covers vary considerably in size and shape and seldom lie Hat on the tub. Butter tubs, as now made, are very strong and tight containers, but it is a fact that the present l0osely fastened, warped and poorly fitted covers serve to eopardize the contents of this otherwise tight container.

In order to better protect the valuable contents of butter tubs from exposure to the contaminating odors and foreign matter to which fine butter is extremely susceptible, I have devised a simple cover securing means which adapts itself to a tight fitting contact with the uneven surfaces on both cover and tub while it also exerts a positive downward pressure on the cover to force it into snug contact with the top of the tub. For this purpose I provide a circumferential groove 14 about the outside of the tub, and this groove serves to form a shoulder 15 with an upwardly inclined lower surface 16 extending around about the upper edge of the tub 10. The downwardly inclined surface 13 of the cover 12 is disposed above the shoulder 15, so that these oppositely inclined surfaces 13 and 16 cooperate in forming a wedgeshaped periphery enclosing the joint between the cover and tub, with the flattened, oppositely inclined surfaces flaring inwardly, as

shown in Fig. 7. To cooperate with these inclined surfaces, I have devised a metal rim 17 which is substantially semi-circular in cross-section, and which is arranged around said wedge-shaped periphery and provided with narrow flanges 18 at both edges thereof. The narrow flanges 18 are preferably curved inwardly and are normally spaced from the inner surface of the rim 17, as shown in Fig. 6, and these flanges are preferably provided with flat portions 19 which converge inwardly toward the middle of the rim, as shown in Fig. 6.

I prefer to form the rim 17 in two identical semicircular sections having over-lapping ends 20 and 21 which are arranged to telescope, as the flanges 18 are cut away for a short distance on the end 20 to allow this end to slide within the spaces between the flanges 18 and the inner surface of the end 21, to be guided therein, as shown in Fig. 8. In order to prevent the telescoped ends 20 and 21 from separating when the rim is drawn tightly into place on the tub, I provide a tongue 22 on the end 20 which extends through a transverse slit 23 in the end 21, as shown in Fig. 4, and this tongue is adapter to be bent back against the rim, as shown in Fig. 3, so as to form a hook which serves to secure the rim in its contracted position. The tongue 22 is easily straightened into its original form when it is necessary to remove the cover from the tub, and the point 24 of this tongue may be bent upon itself, as shown in Figs. 4 and 5, to prevent its pulling through the slit 23, and thus keep the sections of the rim from separating when removed from the tub. In this manner, a telescoping slip-joint is provided at the ends of the overlapping rim sections which allow contraction and expansion of the rim without separation of said ends.

In application: A suitable tool will be provided for forcibly contracting the rim 17 about the tub and cover, and, while the rim is being forced into place, the narrow flanges 18 will engage the oppositely inclined surfaces 13 and 16 which simultaneously act as a wedge to force the cover downwardly into snug contact with the entire upper edge of the tub, and, as the flanges 18 are spaced from the rim, these flanges will collapse during this operation so as to yieldingly adapt themselves to an uneven contour on both inclined surfaces 13 and 16, and thus effect a continuous contact around both cover and tub to serve as additional sealed joints above and below the pressed tight joint between said cover and tub. (it).

It is to be understood that the semi-circular, outwardly curved portion of the rim 17 is normally spaced from both cover edge and tub, so that the flanges 18 are free to act on the inclined surfaces 18 and 16, as shown in Fig. 7, and yet, if the rim should be unduly contracted in the application thereof so that the inside surface of said rim would be forced against said cover and tub, this would not adversely affect the downward pressure of the flanges which would, in such case, already be tensioned for this purpose.

From the above specification it will be apparent that I have invented a simple and effective improvement in the art of butter tub manufacture, on which I submit the following claims.

Claims;

1. In combination with a tub cover having a downwardly inclined upper edge disposed above a ledge on the upper edge of a tub, and a metal band having inwardly extending edges arranged about the adjacent peripheries of said cover and ledge, of reversely turned flanges provided on the edges of said band, for the purpose specified.

2. In combination with a tub cover having a downwardly inclined upper edge disposed above an upwardly inclined shoulder on the upper edge of a tub, and a metal band having inwardly extending edges arranged about the adjacent peripheries of said cover and shoulder, of reversely turned flanges providcd on the edges of said band and normally spaced from the inside of said band, for the purpose specified.

3. In combination with a tub cover having a downwardly inclined upper edge disposed above an upwardly inclined shoulder on the upper edge of a tub, and a metal band having inwardly extending edges arranged about the adjacent peripheries of said cover and shoulder, of reversely turned flanges provided on the edges of said band and normally spaced from. the inside of said band, telescoping ends forming a slip-joint to allow contraction and expansion of said band, and means for inter-locking said telescoping ends, substantially as described.

4. In combination with a tub cover having a downwardly inclined upper edge disposed above an upwardly'inclined shoulder on the upper edge of a tub, and a metal band having inwardly extending edges arranged about the adjacent peripheries of said cover and shoulder, of reversely turned flanges provided on the edges of said band and normally spaced from the inside of said hand, one end of said band being shaped to slide within the spaced flanges on the other end of said band to telescope said ends, and suitable means for interlocking said telescope d ends, substantially as described.

In witness whereof, I have hereunto set my hand this 14th day of November, 1930.

AXEL M. NALSTROM. 

